According to conventional thought about black bears, they have a “home range.” This idea came about because of telemetry studies done beginning in the 1960, where bears were outfitted with a collar which sent a signal. This signal was picked up by an antenna carried by a biologist, or usually a team of people taking turns, and then the bear’s direction was recorded. Basically al the info they had was “The bear is over there and moving that way.”

Once the person running the telemetry unit got really good at it, they could also make some pretty good guestimates of the distance the bear was from the unit by the strength of the signal. Over time, state game departments compiled their information and came up with some general guidelines about where bears spend their time. Areas in which the bears spent the majority of their time became known as their “Home Range.”

Some general numbers became the accepted based on these studies. They go something like this: Female bears have a home range of from 2.5 square miles to 10 square miles or an average of about 6 square miles. Male black bears have a home range of from 10 to 59 square miles or an average of about 35 square miles.

A square mile is 640 acres if you want to get a feel for how much territory that entails. In a moment I will tell you why I believe these estimates are deceiving, but first look at some other factors. The availability of food sources and cover has a lot to do with the amount of ground they cover and the size of their daily movements. The time of the year is also important. No doubt male bears cover a lot more ground during the June and July breeding season than they do when they are settled into a feeding pattern in the late summer and fall.

Of course these numbers clearly point out that bears are individuals and the amount of ground they cover may have a lot to do with their “personality” than many other factors. Some bears just have a wanderlust that others don’t.

But we need to be careful about how we look at the number s in terms of square miles, because I believe that gives us a skewed view of how bears travel and use the landscape. If you grew up in farm country like I did for most of my youth, you know exactly what a square mile looks like. Where I grew up in Iowa, darn near every square mile has a road all the way around it. I can easily look at a piece of property and give a pretty close guess about how many acres it is. So like most people, I think in terms of blocks of land. That’s not a good idea when it comes to think about the areas where bears spend the majority of their time.

Let’s take an average sow bear which spends the majority of her time in a five-acre “Home Range.” Rather than a large block of timber, she may spend most of her time in an area that consists of four miles of shoreline of a lake and swamp, a couple miles each on two creeks that run into the lake and a couple ridges connecting the two creek valleys.

That doesn’t look like five square miles at all, but that’s her home range. Until July of course, when she heads off a couple miles to a timber cut where she spends a couple weeks feeding in blueberries. Then September rolls around and she heads a couple miles the other direction and spends a couple weeks on a ridge where the white oaks are dropping their acorns. Conflict with other bears can cause a bear to adjust their ranges; so can hunting pressure or just human presence such as campers or berry pickers.

Even in excellent bear habitat, bears are not confined to a home range. They must find places where they can be secure and have the best available food. So we must be very careful when we consider limiting bears to a specific area where they spend most of their time, especially when we start thinking about these areas a blocks of land.

Male bears travel a lot more than sows. Mature males will seek out the best available food and claim it for themselves. They may travel for many miles to get to preferred seasonal foods. There are few if any land barriers that can stop them. They go where they want to go.

At one time I advised people to put bear baits at least two miles apart in order to avoid having bears that frequent both baits. I would say that is a good rule of thumb in areas where the habitat is good and food is abundant. But that’s never stopped some bears from visiting multiple baits even farther apart than that. This past September, I had a big male bear that was frequenting my bait most every evening for more than a week leading up to the season, then he just disappeared. A few days later, I got him on camera at another of my baits more than five miles away. Just that one picture; in the night. Just that one picture and never saw him at the other bait again.

While we can accept some generalities that help us understand how bears travel and what specific areas they spend most of their time, there are some outliers. And outfitter friend of mine once told me a story about trailing a bear for many miles in Saskatchewan. It was in May so the first tingling of the rut was getting the male bears on their feet. The outfitter was out running baits following a snowfall that revealed the tracks of a big male bear in the logging road. These tracks turned off the road and went to a bait. After checking that bait, the guides headed back down the logging road only to find the tracks going their way. Sure enough, a little over two miles away, these tracks proved the bear made a visit to the second bait was well. Then a couple miles later, the bear hit the third bait.

Long story short, there were seven baits along that road in all over 14 miles of travel and the bear had checked every single one of them. That’s a lot of travel for one night, and then you must consider the likelihood that the bear must have known where all those baits were from previous experience so he’d probably done this road trip before.

In one of the most unbelievable circumstances I have ever heard, a black sow with three color-phase cubs was run off an outfitter’s bait by a big male bear in mid-afternoon as related by the hunter who was at the bait and witnessed the exchange. He’d snapped a couple photos of the bears before she left in a hurry. Back at camp that night, one of the other hunters related that he had seen a sow with three little cubs at his bait not long before dark. When he said that the sow was black but the cubs were brown, it sparked the interest of the other hunter. They compared photos and both agreed without a doubt it was the same four bears. How far apart were the two baits? As the crow flies, 8-1/2 miles. That’s a lot of ground to cover in just a few hours.

But here’s a situation that will destroy all the home range metrics. A male bear was being studied in the western U.P. of Michigan near Crystal Falls. It was ear-tagged and collared on June 22, 2014. It weighed 230 pounds. Later that year, it slipped its collar and the researchers lost track of it. On September 20, 2015, the bear was shot at a bear bait by Don Mathieu in Barron county, Wisconsin, more than 200 miles away. The bear field dressed at 320, its live weight was estimated at 380 pounds.

I have been seriously studying black bears, bear behavior and bear hunting for most of my life and I’ve learned a lot about bears. But there is only one thing I really know for sure. The more I learn about black bears, the more I realize how much more there is to learn. Their home ranges and movement patterns are a good example of this.

Permalink: /2021/4/black-bear-home-ranges